{"id":"DEBIAN-CVE-2026-49837","details":"GoBGP is an open source Border Gateway Protocol (BGP) implementation in the Go Programming Language. Versions prior to 4.6.0 contain a BGP OPEN capability parsing issue where several concrete capability decoders may parse data from the full remaining capability buffer instead of the slice bounded by the declared capability length, `CapLen`. A malformed BGP OPEN message can cause bytes from a following capability to be interpreted as part of the current capability. The most security-relevant case is the 4-octet AS capability, where a capability with `CapLen == 0` may cause the parser to read bytes from the following capability as the 4-octet AS value. This parsed value may later affect peer AS validation during BGP session establishment. Version 4.6.0 patches the issue.","modified":"2026-09-17T08:47:37.953349582Z","published":"2026-09-10T22:16:57.507Z","upstream":["CVE-2026-49837"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-49837"}],"affected":[{"package":{"name":"gobgp","ecosystem":"Debian:12","purl":"pkg:deb/debian/gobgp?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.10.0-1","3.16.0-1","3.19.0-1","3.21.0-1","3.23.0-1","3.25.0-1","3.27.0-1","3.28.0-1","3.29.0-1","3.30.0-1","3.31.0-1","3.32.0-1","3.33.0-1","3.35.0-1","3.36.0-1","3.36.0-2","4.3.0-1","4.4.0-1","4.5.0-1","4.5.0-1~bpo13+1","4.6.0-1","4.6.0-2","4.6.0-2~bpo13+1","4.7.0-1","4.7.0-1~bpo13+1","4.8.0-1","4.8.0-2~exp1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49837.json"}},{"package":{"name":"gobgp","ecosystem":"Debian:13","purl":"pkg:deb/debian/gobgp?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.36.0-2","4.3.0-1","4.4.0-1","4.5.0-1","4.5.0-1~bpo13+1","4.6.0-1","4.6.0-2","4.6.0-2~bpo13+1","4.7.0-1","4.7.0-1~bpo13+1","4.8.0-1","4.8.0-2~exp1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49837.json"}},{"package":{"name":"gobgp","ecosystem":"Debian:14","purl":"pkg:deb/debian/gobgp?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.6.0-1"}]}],"versions":["3.36.0-2","4.3.0-1","4.4.0-1","4.5.0-1","4.5.0-1~bpo13+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49837.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}